Replacement card arrived yesterday and other than still having the blue lines where the gigabyte bios splash screen should be (it’s the very first thing that’s shown at startup and it’s identical to how it was last time) it’s running okay. An odd thing is though that the driver dates and numbers are different this time and I installed an older one to begin with and had a total lock up in DCS and had to hard reset but on starting up again there had been no blue screen or Windows error or crash dumps. Installed the latest drivers and runs fine now, ran a long mission over and over and no crashes.
So other than the blue lines (which I’m assuming the graphics driver isn’t loading at that point?) It seems okay.
Odd about the driver dates and version numbers though.
Yes, the drivers will only be loaded later in the boot process by the operating system.
However, the firmware on both your mainboard and your gpu are not as dumb as they used to be. So at that stage in the startup there‘s already quite high level software which checks signatures for secure boot, handles DRM crap and in general makes things work even if no OS is booted yet. The term to search for is UEFI, it replaces what was called a BIOS. Both are firmware, but UEFI is a more recent standard and we all use it nowadays.
Long story short: Maybe some change in the UEFI settings could improve things. No idea what, though.
Just read about UEFI and sounds like it’s possible to flash it onto boards but I’m not sure with the only problem being not seeing the Gigabyte BIOS splash screen I would want to risk it and I might just leave it as is. As long as I know the F keys to press it will still work. Thanks for the heads up on it though 
Your board comes with either a BIOS or a UEFI style firmware. No need to change that. I‘m just talking about configuring it. For example most vendors add some downward-compatibility features to their UEFI. To be compatible with devices that still expect a BIOS to be there.
Anyway, it‘s all a bit confusing. If it works now, all is good. Have fun!
Ah I see what you mean now! 
So the new card could be expecting to see UEFI?
Pretty sure it can work with both, in theory. Maybe there‘s some minor hickup.
These things are hard to troubleshoot as there is a certain complexity behind the curtain, but no logs for us to see. So googling or poking around in the settings are the only ideas I have.